Chapter 06 Author: Lee Hannah

FIGURE 6.1 Pangaea (a), Laurasia and Gondwanaland (b). (a) Courtesy of Canadian Geographic. (b) From Wikimedia Commons.

FIGURE 6.2 Distribution of Forest Types, 90 Million Years Ago. Warm rain forest existed at high latitudes in the warm climate of this period. Global mean temperature was much warmer at this time than at present (see inset). Adapted from Bush, M. B. and Flenley, J. R., Tropical Rainforest Response to Climate Change. Springer- Praxis.

FIGURE 6.3 Distribution of Warm Rain Forest and Warm Seasonal Forest 55 Million Years Ago, Near the Early Eocene Climatic Optimum (inset). Adapted from Bush, M. B. and Flenley, J. R., Tropical Rainforest Response to Climate Change. Springer-Praxis.

FIGURE 6.4 Distribution of Warm Rain Forest and Warm Seasonal Forest 30 Million Years Ago, Just After the Global Cooling Associated with the Formation of Antarctic Ice Sheets (inset). Adapted from Bush, M. B. and Flenley, J. R., Tropical Rainforest Response to Climate Change. Springer- Praxis.

FIGURE 6.5 Distribution of Warm Rain Forest and Warm Seasonal Forest 15 Million Years Ago. Adapted from Bush, M. B. and Flenley, J. R., Tropical Rainforest Response to Climate Change. Springer-Praxis.

FIGURE 6.6 Present Distribution of Warm Rain Forest and Warm Seasonal Forest. Adapted from Bush, M. B. and Flenley, J. R., Tropical Rainforest Response to Climate Change. Springer-Praxis.

FIGURE 6.7 Present and Last Glacial Maximum Vegetation Formations and Biomes. Pollen analysis can be used to assign vegetation formations and biomes for past climates. The top panel shows vegetation formations and biomes inferred from analysis of current pollen rain. The middle panel shows the actual current vegetation formations and biomes. The bottom panel shows vegetation formations and biomes for the Last Glacial Maximum, inferred from pollen data. From Jackson, S. T., et al., Vegetation and environment in Eastern North America during the Last Glacial Maximum. Quaternary Science Reviews 19, 489 – 508.

FIGURE 6.8 Drilling a Pollen Core from a Lake Bed. Paleoecologist Nicole Sublette lowers a coring device to a lake fl oor in the Peruvian Andes with help from Eric Mosblech, a teacher volunteer participating in a fi eld expedition as a means to improve high school curriculum development. Courtesy of Mark Bush, Eric Mosblech, and Nicole Sublette.

FIGURE 6.9 Macrofossil and Pollen Records Near the Laurentide Ice Sheet. Trace pollen amounts interpreted as wind-blown input from distant forests in many studies may actually represent pollen micropockets near the ice sheet. Macrofossil records indicate the presence of forest trees near the ice sheet even in times for which little pollen has been recorded from these locations. Jackson, S. T., et al Mapped plant-macrofossil and pollen records of late quaternary vegetation change in eastern North America. Quaternary Science Reviews 16, 1 – 70.

FIGURE 6.10 Younger Dryas Temperature Fluctuation. The Younger Dryas is a millennial-scale cool period (shaded area) initiated by a rapid cooling and ended by rapid warming. Source: Redrawn from Alley, 2007.

FIGURE 6.11 Dryas Octopetala, Known Commonly as Mountain Avens or White Dryas. From Wikimedia Commons.

FIGURE 6.12 Greenland Ice Core. Courtesy of NASA/JSC.

FIGURE 6.13 Vegetation Change in Tropical Southeast Asia. Vegetation types (horizontal bars) and limits (vertical bands) inferred from pollen analyses for sites in Southeast Asia. From Flenley, J. R Tropical forests under the climates of the last 30,000 years. Climatic Change 39, 177 – 197.

FIGURE ,000 Years of Change in the Tropical Andes. Paleotemperature and paleoelevation inferred from pollen spectra from Lago Consuelo, Peru. Color indicates the probability that a sample came from that elevation or temperature (blue, low; orange, high). Note that time runs right to left in this fi gure. Reproduced with permission from AAAS.